1 - The step link installs when stepping the mast only. It may require some drilling on an old model 14. There should be a hole across the back of the step casting where the link fits in. There should be a hole in the mast base as well. THe link connects these two parts. Look at the link, get it right side up and note the H14 hole (this link works on a 16 as well). Bolt the link to the step casting and pin to the mast base when putting the mast up or down.

2 - H14s rigs can be sailed loose. Grab the shroud wire and make a fist around it. You should be able to trun your fist 90 degrees to the wire with the slack. You can always tighten the rig, but this is the loosest it should be. Be sure that the base of the mast cannot come out of the step cup if the mast lifts up in a capsize. 14 Turbo rigs (with jibs) should be tight.

3 - The boom tensioner? That would be called a boom vang. Not many people use a boom vang on Hobie cats. That can hold the boom in a sheeted position if the mainsheet and traveler is let all the way out. Not necessary. The traveler track is long and normally you do not sail with it sheeted all the way out. Vangs are probably more trouble than they are worth on a Hobie.

4 - Not sure what the question is here? A righting kit? Mast stepping Kit?